#!/usr/bin/env node
import { existsSync } from "node:fs";
import { createInterface } from "node:readline";
import { parseArgs } from "node:util";
import { ConfigError, DEFAULT_CONFIG_PATH, loadConfig, parseNodeId, type Config } from "./config.js";
import { commissionedNodeIds, resolveSingleNode, startController } from "./controller.js";
import { commissionDevice } from "./commissioning.js";
import { connectDevice } from "./device.js";
import { formatFabricTable, readFabricTable, removeFabricByIndex } from "./fabrics.js";
import { formatInspection, inspectionToJson, inspectNode } from "./inspection.js";
import { Log, describeError, setLogLevel } from "./logging.js";
import { currentMatterUtcMicroseconds, isHostClockSynchronized } from "./sync.js";
import { nodeState, readServiceState, removeNodeState, serviceStatePath, updateNodeState } from "./state.js";
import { formatUtcOffset, nextOffsetTransition, utcOffsetSeconds } from "./timezone.js";

const log = new Log("cli");

const USAGE = `Usage: mattertimesync [--config <path>] <command> [options]

Commands:
  commission [--code <pairing-code>]     Commission a device as an additional Matter admin
  nodes                                  List commissioned devices and their sync state
  inspect [--node <id>] [--json]         Dump a device's endpoints, clusters, time capabilities
  sync [--node <id>]                     Synchronize device clocks (not yet implemented)
  status                                 Show controller and per-device state
  fabrics [--node <id>] [--remove <n>]   List a device's fabric table; remove a stale entry
  decommission --node <id>               Remove this controller from a device

The controller fabric is the device registry: every commissioned node is kept
in sync. --node may be omitted while only one device is commissioned.
Run "sync" periodically (e.g. from a systemd timer) to keep clocks correct.

Options:
  --config <path>   Configuration file (default: ${DEFAULT_CONFIG_PATH})
  --help            Show this help
`;

async function main(): Promise<number> {
  const { values, positionals } = parseArgs({
    options: {
      config: { type: "string" },
      code: { type: "string" },
      json: { type: "boolean", default: false },
      node: { type: "string" },
      remove: { type: "string" },
      help: { type: "boolean", default: false },
    },
    allowPositionals: true,
  });

  if (values.help || positionals.length === 0) {
    process.stdout.write(USAGE);
    return values.help ? 0 : 2;
  }

  const command = positionals[0]!;
  const configPath = values.config ?? DEFAULT_CONFIG_PATH;

  let config: Config;
  let requestedNode: bigint | undefined;
  try {
    config = loadConfig(configPath);
    requestedNode = values.node === undefined ? undefined : parseNodeId(values.node);
  } catch (cause) {
    if (cause instanceof ConfigError) {
      process.stderr.write(`Configuration error: ${cause.message}\n`);
      return 1;
    }
    throw cause;
  }
  setLogLevel(config.logLevel);

  switch (command) {
    case "commission":
      return await runCommission(config, values.code);
    case "nodes":
      return await runNodes(config);
    case "inspect":
      return await runInspect(config, requestedNode, values.json ?? false);
    case "sync":
      return runNotImplemented("sync");
    case "status":
      return await runStatus(config);
    case "fabrics":
      return await runFabrics(config, requestedNode, values.remove);
    case "decommission":
      return await runDecommission(config, requestedNode);
    default:
      process.stderr.write(`Unknown command "${command}"\n\n${USAGE}`);
      return 2;
  }
}

async function runCommission(config: Config, codeArgument: string | undefined): Promise<number> {
  const pairingCode = codeArgument ?? (await promptForPairingCode());
  const controller = await startController(config);
  try {
    const result = await commissionDevice(controller, config, pairingCode);

    const node = await connectDevice(controller, result.nodeId);
    updateNodeState(serviceStatePath(config.storagePath), result.nodeId, {
      lastSuccessfulConnection: new Date().toISOString(),
    });
    const report = await inspectNode(node);
    process.stdout.write(formatInspection(report) + "\n\n");

    process.stdout.write(
      [
        "Commissioning summary",
        `  Node ID:        ${result.nodeId}`,
        `  Fabric ID:      ${controller.fabric.fabricId}`,
        `  Total devices:  ${commissionedNodeIds(controller).length}`,
        `  Time Sync:      ${
          report.timeSynchronization
            ? `endpoint ${report.timeSynchronization.endpointId}`
            : "cluster not found"
        }`,
        "",
        "The device remains paired with its primary ecosystem; this controller",
        "was added as an additional Matter administrator. Time synchronization",
        "commands will be implemented from this inspection data (plan Phase 5).",
        "",
      ].join("\n"),
    );
    return 0;
  } finally {
    await controller.close();
  }
}

async function runNodes(config: Config): Promise<number> {
  const controller = await startController(config);
  try {
    const details = controller.getCommissionedNodesDetails();
    if (details.length === 0) {
      process.stdout.write('No devices commissioned. Run "commission" to add one.\n');
      return 0;
    }

    const state = readServiceState(serviceStatePath(config.storagePath));
    process.stdout.write(`${details.length} commissioned device${details.length === 1 ? "" : "s"}:\n`);
    for (const detail of details) {
      const nodeId = BigInt(detail.nodeId);
      const info = detail.deviceData.basicInformation ?? {};
      const name = [info["vendorName"], info["productName"]].filter(Boolean).join(" ");
      const perNode = nodeState(state, nodeId);
      process.stdout.write(
        [
          `  node ${nodeId}: ${name || "(no cached device info)"}`,
          `    last connection: ${perNode.lastSuccessfulConnection ?? "never"}`,
          `    last sync:       ${perNode.lastSuccessfulSync ?? "never"}`,
          ...(perNode.lastError !== null ? [`    last error:      ${perNode.lastError}`] : []),
        ].join("\n") + "\n",
      );
    }
    return 0;
  } finally {
    await controller.close();
  }
}

async function runInspect(config: Config, requestedNode: bigint | undefined, json: boolean): Promise<number> {
  const controller = await startController(config);
  try {
    const nodeId = resolveSingleNode(controller, requestedNode);
    const node = await connectDevice(controller, nodeId);
    updateNodeState(serviceStatePath(config.storagePath), nodeId, {
      lastSuccessfulConnection: new Date().toISOString(),
    });
    const report = await inspectNode(node);
    process.stdout.write((json ? inspectionToJson(report) : formatInspection(report)) + "\n");
    return 0;
  } finally {
    await controller.close();
  }
}

function runNotImplemented(command: string): number {
  process.stderr.write(
    `"${command}" is not implemented yet. Per the project plan, the Time Synchronization\n` +
      `write commands are implemented only after inspecting the real device.\n` +
      `Run "commission" and then "inspect --json" against the hardware first.\n`,
  );
  return 3;
}

async function runStatus(config: Config): Promise<number> {
  const statePath = serviceStatePath(config.storagePath);
  const state = readServiceState(statePath);
  const storageExists = existsSync(config.storagePath);
  const ntpSynchronized = await isHostClockSynchronized();
  const offsetSeconds = utcOffsetSeconds(config.timezone);
  const transition = nextOffsetTransition(config.timezone);

  const nodeIds = Object.keys(state.nodes);
  const lines = [
    `Configuration:        loaded (${config.timezone})`,
    `Controller storage:   ${storageExists ? `present at ${config.storagePath}` : "NOT INITIALIZED"}`,
    `Commissioned nodes:   ${nodeIds.length > 0 ? nodeIds.join(", ") : "none recorded"}`,
    `Host NTP synced:      ${ntpSynchronized ? "yes" : "no (or not determinable on this host)"}`,
    `Current UTC offset:   ${formatUtcOffset(offsetSeconds)}`,
    `Next DST transition:  ${
      transition
        ? `${transition.at.toISOString()} (${formatUtcOffset(transition.offsetBeforeSeconds)} -> ${formatUtcOffset(
            transition.offsetAfterSeconds,
          )})`
        : "none within 400 days"
    }`,
    `Matter time now:      ${currentMatterUtcMicroseconds()} us since 2000-01-01T00:00:00Z`,
  ];
  for (const [nodeId, perNode] of Object.entries(state.nodes)) {
    lines.push(`Node ${nodeId}:`);
    lines.push(`  Last connection:      ${perNode.lastSuccessfulConnection ?? "never"}`);
    lines.push(`  Last successful sync: ${perNode.lastSuccessfulSync ?? "never"}`);
    lines.push(`  Last attempted sync:  ${perNode.lastAttemptedSync ?? "never"}`);
    lines.push(`  Most recent error:    ${perNode.lastError ?? "none"}`);
  }
  process.stdout.write(lines.join("\n") + "\n");
  return 0;
}

async function runFabrics(
  config: Config,
  requestedNode: bigint | undefined,
  removeArgument: string | undefined,
): Promise<number> {
  let removeIndex: number | undefined;
  if (removeArgument !== undefined) {
    removeIndex = Number(removeArgument);
    if (!Number.isInteger(removeIndex) || removeIndex < 1) {
      process.stderr.write(`--remove requires a positive fabric index (got "${removeArgument}")\n`);
      return 2;
    }
  }

  const controller = await startController(config);
  try {
    const nodeId = resolveSingleNode(controller, requestedNode);
    const node = await connectDevice(controller, nodeId);

    if (removeIndex !== undefined) {
      await removeFabricByIndex(controller, node, removeIndex);
    }

    const table = await readFabricTable(controller, node);
    process.stdout.write(formatFabricTable(nodeId, table) + "\n");
    return 0;
  } finally {
    await controller.close();
  }
}

async function runDecommission(config: Config, requestedNode: bigint | undefined): Promise<number> {
  const controller = await startController(config);
  try {
    const nodeId = resolveSingleNode(controller, requestedNode);
    const node = await connectDevice(controller, nodeId);

    log.info(`Decommissioning: removing this controller's fabric from node ${nodeId}`);
    await node.decommission();

    removeNodeState(serviceStatePath(config.storagePath), nodeId);
    const remaining = commissionedNodeIds(controller);
    process.stdout.write(
      [
        `Device ${nodeId} removed this controller's fabric; its primary ecosystem is untouched.`,
        remaining.length > 0
          ? `${remaining.length} device${remaining.length === 1 ? "" : "s"} remain commissioned: ${remaining.join(", ")}.`
          : `No devices remain commissioned. Local controller identity remains in ` +
            `${config.storagePath}; deleting that directory is now safe, or keep it to reuse ` +
            `the same identity for future commissioning.`,
        "",
      ].join("\n"),
    );
    return 0;
  } finally {
    await controller.close();
  }
}

async function promptForPairingCode(): Promise<string> {
  if (!process.stdin.isTTY) {
    throw new Error("No pairing code given. Pass --code <pairing-code> when not running interactively.");
  }
  const readline = createInterface({ input: process.stdin, output: process.stdout });
  try {
    const answer = await new Promise<string>(resolve =>
      readline.question("Matter pairing code (from the primary ecosystem's pairing mode): ", resolve),
    );
    return answer.trim();
  } finally {
    readline.close();
  }
}

main()
  .then(code => {
    process.exitCode = code;
  })
  .catch(cause => {
    log.error("Fatal error", cause);
    if (!(cause instanceof Error)) {
      process.stderr.write(describeError(cause) + "\n");
    }
    process.exitCode = 1;
  });